Locus minoris resistentiae

This acid profile demonstrates that in a normal physiologic state, the human condition (gastric) is consistent with periods of high acidity without either discomfort or disease. Mucosal damage incited by a wide variety of agents provides the locus minoris resistentiae. 

The double bond of N-acylenamino acids and their esters represents the locus minoris resistentiae . As a result of conjugation with the carboxyl group, the double bond is a good acceptor for nucleophilic addends under basic catalysis. The acylamino group makes electrophilic additions possible. It is thus possible to obtain a- or P-mercapto a-amino acid derivatives by selecting the appropriate reaction conditions for the addition of mercaptans. 

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